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Technical Paper

Adaptation of the Cognitive Avionic Tool Set (CATS) into Automotive Human Machine Interface Design Process

DENSO International America, Inc. and the University of Iowa-Operator Performance Laboratory (OPL) have developed a series of new Multi-Modal Interface for Drivers (MMID) in order to improve driver safety, comfort, convenience and connectivity. Three MMID concepts were developed: GUI 1, GUI 2 and GUI 1-HUD. All three of the MMIDs used a new Reconfigurable Haptic Joystick (RHJ) on the steering wheel and new concept HMI Dual Touch Function Switches (DTFS) device. The DTFS use capacitive and mechanic sensing located on the back of the steering wheel as input operation devices. Inputs from the new controls were combined with a large TFT LCD display in the instrument cluster, a Head Up Display (HUD) and Sound as output devices. The new MMID system was installed in a Lexus LS-430. The climate control panel and radio panels of the LS-430 were used as a baseline condition to which the new designs were compared.
Technical Paper

Development of High Performance Radiators by Fin Optimization

Requirements for fuel economy improvement and reduction in the vehicles engine compartment have increased significantly in the pass years. Performances in radiators have driven changes in terms of compactness and weight reductions. By focusing on the air flow we have optimized the radiator fin and developed a high performance radiator. A similar performance was achieved using an 11mm core depth which has 30% weight reduction compared to a 16mm core depth. The purpose of this paper is to present a technical outline about fin optimization.
Technical Paper

Reduction of the BPF Noise Radiated from an Engine Cooling Fan

This study investigates the reduction of the Blade Passing Frequency (BPF) noise radiated from an automotive engine cooling fans, especially in case of the fan with an eccentric shroud. In recent years, with the increase of HV and EV, noise reduction demand been increased. Therefore it is necessary to reduce engine cooling fan noise. In addition, as a vehicle trend, engine rooms have diminished due to expansion of passenger rooms. As a result, since the space for engine cooling fans need to be small. In this situation, shroud shapes have become complicated and non-axial symmetric (eccentric). Generally, the noise of fan with an eccentric shroud becomes worse especially for BPF noise. So it is necessary to reduce the fan BPF noise. The purposes of this paper is to find sound sources of the BPF noise by measuring sound intensity and to analyze the flow structure around the blade by Computational Fluid Dynamics (CFD).
Technical Paper

Study of Cooling Drag Reduction Method by Controlling Cooling Flow

As the demand for improved fuel economy increases and new CO2 regulations have been issued, aerodynamic drag reduction has become more critical. One of the important factors to consider is cooling drag. One way to reduce cooling drag is to decrease the air flow volume through the front grille, but this has an undesirable impact on cooling performance as well as component heat load in the under-hood area. For this reason, cooling drag reduction methods while keeping reliability, cooling performance and component heat management were investigated in this study. At first, air flow volume reduction at high speed was studied, where aerodynamic drag has the greatest influence. For vehicles sold in the USA, cooling specification tends to be determined based on low speed, while towing or driving up mountain roads, and therefore, there may be extra cooling capacity under high speed conditions.
Technical Paper

The Large Scale Finite Element Analysis of a Charge Air Cooler Using a Homogenization Method

Heat exchangers used as charge air coolers are repeatedly subjected to thermal strain, which may cause fracture. To predict the durability of heat exchangers, stress estimations using Finite Element Analysis (FEA) are effective. However, producing a detailed finite element model would require an enormous number of elements and excessive calculation costs. To resolve this problem, we focused on periodic tube-fin structures, considering actual and designed fin shapes, and applied a homogenization method to the fins. We then determined their homogenization elastic stiffness and verified it by conducting compression experiments and analyses using partial models consisting of laminated tube-fin structures. If fins are homogenized, it is important that homogenization be based on the actual fin shape. We then produced a finite element model of a charge air cooler assembly by using the homogenization element, and conducted analyses which simulated a thermal fatigue test.
Technical Paper

Automotive Electric System Level Design Methodologies with SystemC

ESL (Electric System Level) Design Methodologies enable us to design and verify various electrical behaviors of automotive electronics including automotive semiconductors on a simulator before hardware prototyping. It could facilitate the optimization of hardware structures, and shorten the total development period by reducing rework process. We propose the “ESL Design Methodologies for Automotive” to renovate conventional development scheme. ESL technology began to be used from the domain of digital consumer electronics. Regarding automotive electronics domain, however, we would not be able to adapt the same methodologies to automotive systems, which consist of many mixed-signal components. Also, another approach is required for the rising demand of safety design sort of functional safety.
Technical Paper

Study of Ignition System for Demand Voltage Reduction

Improving the engine efficiency to respond to climate change and energy security issues is strongly required. In order to improve the engine efficiency, lower fuel consumption, and enhance engine performance, OEMs have been developing high compression ratio engines and downsized turbocharged engines. However, higher compression ratio and turbocharging cause cylinder pressure to increase, which in turn increases the demand voltage for ignition. To reduce the demand voltage, a new ignition system is developed that uses a high voltage Zener diode to maintain a constant output voltage. Maintaining a constant voltage higher than the static breakdown voltage helps limit the amount of overshoot produced during the spark event. This allows discharge to occur at a lower demand voltage than with conventional spark ignition systems. The results show that the maximum reduction in demand voltage is 3.5 kV when the engine is operated at 2800 rpm and 2.6 MPa break mean effective pressure.
Journal Article

Proper Orthogonal Decomposition Analysis of Flow Structures Generated around Engine Cooling Fan

A cooling fan is one of the primary components affecting the cooling performance of an engine cooling system. In recent years, with the increase in electric vehicles (EVs) and hybrid vehicles (HVs), the cooling performance and noise level of the cooling fan have become very important. Thus, the development of a low-noise fan with the same cooling performance is urgently required. To address this issue, it is critical to find the relation between the performance of the fan and the flow structures generated around it, which is discussed in the present paper. Specifically, a computational method is employed that uses unsteady Reynolds-averaged Navier-Stokes (URANS) coupling with a sliding mesh (SLM). Measurements of the P-Q (Pressure gain-Flow rate) characteristics are performed to validate the predictive accuracy of the simulation.